finding the pivot of the camera using python
You're looking in the wrong place basically. What you need to do is get the RegionView3D of whatever 3d window you want to get the pivot point (view_location) of.
API docs
Something like this should work:
import bpy

def get_rv3d():
    for area in bpy.context.screen.areas:
        if area.type == 'VIEW_3D':
            rv3d = area.spaces[0].region_3d
            if rv3d is not None:
                return rv3d
    return None
            
rv3d = get_rv3d()
if rv3d:
    print(rv3d.view_location)